Lasers are ubiquitous devices used for testing, measuring, printing, cutting, marking, medical applications, communications, data transmission, semiconductor processing, and a number of other applications. Many types of lasers have been developed to meet different performance criteria for different applications. Engraving, cutting, marking, printing, and many other applications require relatively compact lasers that generate high power outputs and have beams with a desired shape and energy distribution. Laser-based processing systems, for example, can mark, cut, weld, or perform other types of surface modifications of material for a variety of different applications.
Commonly, laser-based material processing systems have a gantry motion system for moving the laser beam across a material processing area. For example, the motion system can include a moveable arm orientated along an X-axis and configured to travel along a Y-axis of movement by sliding along a pair of Y-axis orientated rails. Optical elements positioned along one of the rails and the moveable arm are configured to capture and redirect a laser beam from a stationary laser source toward a focus carriage that is attached to and moves along the moveable arm to position the focused laser beam at a desired point along the X-axis. The focus carriage typically houses additional optical elements configured to capture and redirect the laser beam toward the material processing area. Accordingly, the gantry motion system arrangement allows the laser beam to be directed to any position within an X-Y field of motion via movement of the arm along the Y-axis and movement of the focus carriage along the arm.
When the focused laser beam irradiates the surface of a target material (i.e., wood, plastic, leather, coated metals, etc.), such as for cutting patterns or engraving images, fumes, particulates, smoke, debris, etc. (i.e., contaminants) are generated at the site of irradiation. If not evacuated, these contaminants can negatively affect and/or damage both the optic and motion system components described above. Accordingly, such contaminants should be extracted from the site of material processing. In some conventional systems, the contaminants are vented away from the processing area, while in other conventional systems, the contaminants are filtered from the air to prevent damage to the system, as well as to prevent exposure to the system operator and/or other bystanders.
Conventional exhausting systems in laser-based material processing applications, for example, typically include enclosing the material processing area and system components in a common housing and then venting the housing low-pressure, high-volume vacuum exhaust blowers. For example, an exhaust manifold connected to an externally located exhaust blower can be positioned along one wall of the housing (i.e., along the X-axis) and a fresh air intake slot can be formed in a wall of the housing opposite of the exhaust manifold. Operation of the exhaust blower produces a negative pressure volume which can direct a so-called “curtain of moving air” across the surface of the material being processed. The laminar air flow produced should be as wide as the motion system field of travel to effectively remove the contaminants. Accordingly, the exhaust blowers must be able to move large volumes of air in order to effectively exhaust all smoke generated during material processing.
Additional exhausting systems can include a flexible exhaust hose directly attached to the focus carriage. In such systems, the exhaust hose moves with the focus carriage during material processing. The nozzle of the exhaust hose is typically orientated proximal to the point of laser irradiation, thereby removing contaminants directly from their point of generation. Such exhaust systems generally rely on exhaust blowers that create higher vacuum pressure but lower air flow for achieving increased exhaust velocities to capture the contaminants quickly before dispersion. Other known arrangements include exhaust systems designed to remove contaminants through a base structure positioned below the material processing area. However, these systems are only effective when cutting through a workpiece. If images are engraved on the surface of the workpiece, for example, these exhaust systems are not effective.